JP3016409B2 - Transmission control device for infinite reduction ratio transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission control apparatus for an infinite reduction ratio transmission combining a continuously variable transmission and a planetary gear mechanism, and more particularly to a transmission mode switching control technique.

[0002]

2. Description of the Related Art Conventionally, as a shift control device of an infinite reduction ratio transmission combining a continuously variable transmission and a planetary gear mechanism,
For example, one described in U.S. Pat. No. 5,045,028 is known.

In the conventional source described above, the transmission is provided in the middle of the transmission path from the unit input shaft 14 of the infinite reduction ratio transmission in which the continuously variable transmission 1 and the planetary gear mechanism 26 are combined to the carrier of the planetary gear mechanism 26. It has a torque split clutch 25 and a direct coupling clutch 33 provided in the middle of a transmission path from the sun gear of the planetary gear mechanism 26 to the unit output shaft. The torque split clutch 25 is engaged, and the speed ratio of the continuously variable transmission 1 is reduced. By controlling, the torque reduction mode including the speed ratio infinity from the negative value (during reverse running) to the positive value (during forward running) including the infinite speed ratio, the direct coupling clutch 33 is engaged, and the total reduction ratio is not controlled. An apparatus for performing shift control for obtaining an optimum gear ratio in accordance with a running state by switching between a gear ratio of a stepped transmission and a direct connection mode is shown.

[0004]

However, in the transmission control device of the conventional infinite reduction ratio transmission described above, the transmission mode switching control does not judge the actual traveling state (forward or backward) of the vehicle. Since this is a device that switches from the torque split mode to the direct connection mode or from the direct connection mode to the torque split mode, the device may switch from the torque split mode to the direct connection mode when reversing, causing failure such as clutch burn or engine stall. I do.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a first object thereof is to provide a speed change control of an infinite reduction ratio transmission combining a continuously variable transmission and a planetary gear mechanism. It is an object of the present invention to achieve smooth transmission mode switching control and to realize transmission mode switching fail-safe when the vehicle is moving backward.

It is a second object of the present invention to achieve smooth transmission mode switching control by means of cost-effective and reliable operation, and to realize transmission mode switching fail-safe when the vehicle moves backward.

[0007]

According to a first aspect of the present invention, there is provided a transmission control apparatus for an infinite reduction ratio transmission, which is connected to a unit input shaft a as shown in FIG. The sun gear is connected to the continuously variable transmission b and the speed reducer c, and the continuously variable transmission output shaft d, and the speed reducer output shaft e
A planetary gear mechanism g in which a ring gear is connected to the unit output shaft f; a torque split clutch h provided in the middle of a transmission path from the unit input shaft a to the carrier of the planetary gear mechanism g; A directly-coupled clutch i provided in the middle of a transmission path from the sun gear of the planetary gear mechanism g to the unit output shaft f, and a continuously variable transmission output rotational speed detecting means j for detecting the rotational speed of the continuously variable transmission output shaft d. A torque split clutch input rotational speed detecting means k for detecting an input rotational speed of the torque split clutch h, a unit output rotational direction detecting means m for detecting a rotational direction of the unit output shaft f, and a continuously variable transmission output. When the rotation speed is higher than the torque division clutch input rotation speed, only the torque division clutch h is engaged, and when the continuously variable transmission output rotation speed is lower than the torque division clutch input rotation speed. A transmission mode switching control means n for engaging only the direct coupling clutch i and maintaining the engagement of the torque split clutch h and prohibiting the engagement of the direct coupling clutch i when the unit output rotation direction is the reverse direction. It is characterized by the following.

According to a second aspect of the present invention, there is provided a transmission control apparatus for an infinite reduction ratio transmission according to a second aspect of the present invention. The number detection means j and the torque split clutch input rotation number detection means k are means using a pitot tube for converting the rotation number into a pitot pressure, and the unit output rotation direction detection means m uses a pitot pressure generated only during reverse travel. The transmission mode switching control means n is a transmission mode switching control valve that operates using each pitot pressure as a signal pressure.

[0009]

The operation of the first invention will be described.

In the transmission mode switching control means n, the transmission mode switching control means n controls the continuously variable transmission output speed detecting means j.
When the output speed of the continuously variable transmission from the motor is higher than the input speed of the torque split clutch from the torque split clutch input speed detecting means k, only the torque split clutch h is engaged, and the speed ratio control range of the continuously variable transmission b. And the reverse range, the neutral range, and the low-side drive range are controlled in the torque split mode, and the output speed of the continuously variable transmission from the continuously variable transmission output speed detecting means j is used to detect the input speed of the torque split clutch. When the rotational speed is lower than the input rotational speed of the torque split clutch from the means k, only the direct coupling clutch i is engaged, and the direct drive mode is set in which the high drive range is controlled within the speed ratio control range of the continuously variable transmission b.

In the transmission mode switching control, when the unit output rotation direction from the unit output rotation direction detecting means m is the reverse direction, the rotation speed condition for setting the direct connection mode due to the failure of the continuously variable transmission b or the like is satisfied. Thus, the engagement of the torque split clutch h is maintained, and the engagement of the direct coupling clutch i is prohibited.

Therefore, smooth transmission mode switching control is achieved by comparing the number of rotations, and the transmission mode is not switched to the direct connection mode when the vehicle is traveling backward, thereby realizing a fail-safe operation in reverse.

The operation of the second invention will be described.

In the continuously variable transmission output speed detecting means j and the torque split clutch input speed detecting means k using the pitot tube, the higher the speed, the higher the pitot pressure is generated. In the unit output rotation direction detecting means m using the pitot tube, the pitot pressure is not generated when the vehicle is moving forward, but is generated only when the vehicle is moving backward.

When the transmission mode switching control valve is operated using the pitot pressure as a signal pressure and the output speed of the continuously variable transmission is higher than the input speed of the torque split clutch, only the torque split clutch h is engaged due to the pitot pressure difference. When the continuously variable transmission output speed is lower than the torque split clutch input speed, the valve position is such that only the direct connection clutch i is engaged due to the pitot pressure difference, and the unit output rotation direction is the reverse direction. At this time, the valve position is such that the engagement of the torque dividing clutch h is held by the pitot pressure and the engagement of the direct coupling clutch i is prohibited.

Therefore, the components of each means described in the first invention
As a physical configuration, each of the detection means j, k, and m is electrically connected.
Rotation sensor and rotation direction sensor that output
Used as the transmission mode switching control means n from each sensor.
Controller and controller for electrically processing sensor signals
Actuator driven by control signal from controller
An electronic control configuration using But the second
In the second invention, a pitot tube is used as each of the detection means j, k, and m.
Transmission mode switching as transmission mode switching control means n
Since a hydraulic control structure called a control valve is adopted, the electronic control structure is used.
The smooth transmission mode switching control of the first aspect of the present invention is achieved by a reliable hydraulic operation which does not require sensors, controllers and actuators used in the construction, and which eliminates the cause of electrical failure. And fail-safe in reverse is realized.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration will be described.

FIG. 2 is an overall block diagram showing an infinite reduction ratio transmission to which the transmission control apparatus according to the first and second embodiments of the present invention is applied.

In FIG. 2, the power transmission system includes a continuously variable transmission 2 and a speed reducer 3 connected to a unit input shaft 1.
A planetary gear mechanism 5 in which a sun gear 5a is connected to the continuously variable transmission output shaft 4, a carrier 5b is connected to the speed reducer output shaft 6, and a ring gear 5c is connected to the unit output shaft 7.
A torque split clutch A provided in the middle of the speed reducer output shaft 6 from the unit input shaft 1 to the carrier 5b of the planetary gear mechanism 5, and a transmission path from the sun gear 5a of the planetary gear mechanism 5 to the unit output shaft 7 Direct coupling clutch B provided
And

The unit input shaft 1 is connected to an engine mounted on a vehicle.

As the continuously variable transmission 2, a V-belt type continuously variable transmission or a toroidal type continuously variable transmission is used.

The speed reducer 3 is set so that its speed reduction ratio matches the maximum speed reduction ratio of the continuously variable transmission 2.

The reduction gear output shaft 6 has a clutch input shaft 6a and a clutch output shaft 6b with the torque split clutch A interposed therebetween.
It consists of.

The unit output shaft 7 is connected to left and right drive wheels via a differential gear.

In FIG. 2, the transmission mode switching hydraulic control system includes a continuously variable transmission output speed detecting pitot tube 10 (a continuously variable transmission output speed detecting means) for converting the continuously variable transmission output speed into a pitot pressure. j), a torque split clutch input speed detecting pitot tube 11 (corresponding to torque split clutch input speed detecting means k) for converting the torque split clutch input speed into a pitot pressure, and a pitot pressure is generated only during reverse travel. Output rotation direction detection pitot tube 12 (corresponding to unit output rotation direction detection means m), transmission mode switching control valve 13 (corresponding to transmission mode switching control means n) operating with each pitot pressure as a signal pressure, and regulator A valve 14 and an oil pump 15 are provided.

Next, the operation will be described.

[Torque split mode] The torque split mode is realized by the torque split clutch A being engaged and the direct coupling clutch B being released.

In this state, since the rotation speed of the carrier 5b is constant when the rotation speed of the unit input shaft is constant, the rotation speed of the unit output shaft 7 is equal to the rotation speed of the output shaft of the continuously variable transmission 2 = By changing the speed of the continuously variable transmission 2 from the speed increasing side to the speed reducing side by the rotation speed of the sun gear 5a, the rotation speed of the ring gear 5c, which is the unit output shaft rotation speed, is changed from reverse (negative) to stop (0). The gear can be shifted to forward rotation.

That is, as shown by the solid line characteristics in FIG.
CVT ratio (stepless speed change ratio) of 0.4 (speed increasing side) to 2.
Between 0 (reduction side), a reverse range, a neutral range, and a low side drive range are controlled, and the speed ratio is represented by an IVT ratio including an infinite reduction ratio.

[Direct-Coupling Mode] The direct-coupling mode is realized by releasing the torque split clutch A and engaging the direct-connection clutch B.

In this state, the speed reducer 3 and the planetary gear mechanism 5 do not participate in the speed change, and the rotation speed of the unit output shaft 7 becomes the output shaft rotation speed of the continuously variable transmission 2. That is, by performing the shift control on the continuously variable transmission 2, it is possible to obtain a forward gear ratio.

That is, as shown by the one-dot chain line in FIG. 3, the CVT ratio (stepless speed change ratio) is from 2.0 (deceleration side) to
The high-side drive range is controlled between 0.4 (increased speed side), and its speed ratio matches the CVT ratio of the continuously variable transmission 2.

[Pitot Pressure Generating Action] In the continuously variable transmission output speed detection pitot tube 10, as shown in FIG. 4 (a), as the sun gear speed NS (= the continuously variable transmission output speed) increases. As a result, a Pitot pressure PNS which rises in a quadratic function curve is obtained.

In the torque split clutch input rotation speed detecting pitot tube 11, as shown in FIG.
A pitot pressure PNC which rises in a quadratic function curve in accordance with an increase in C (= torque split clutch input rotation speed) is obtained.

In the unit output rotation direction detecting pitot tube 12, as shown in FIG. 5, the pitot which rises in a quadratic function curve in accordance with the rise of the ring gear rotation speed NR (= unit output shaft rotation speed) only at the time of reverse travel. A pressure PNR is obtained and the pitot pressure is not at the time of forward movement.

That is, as shown in FIG. 6, the hole of the unit output rotation direction detecting pitot tube 12 is
The arrangement is such that oil is received only when c is in the rotating direction, so that a pitot pressure is generated only when the vehicle is moving in reverse. Therefore, it is hydraulic pressure information that can determine whether the pitot pressure is moving forward or backward.

[Transmission Mode Switching Control Operation] First, as shown in FIGS. 7 and 8, the transmission mode switching control valve 13 includes a spool 13a, a carrier pressure port 13b, a drain port 13c, and a clutch B pressure port 13d. , A line pressure port 13e, a clutch A pressure port 13f, a drain port 13g, a sun gear pressure port 13h, and a ring gear pressure port 13i.

In the neutral range, as shown in FIG. 3, the speed ratio of the continuously variable transmission 2 is set to the speed increasing side of about 0.75. Therefore, the relationship between the sun gear rotational speed NS and the carrier rotational speed NC is NS> NC, and the relationship between the pitot pressure PNS and the pitot pressure PNC is PNS> PNC. As shown in the lower part of FIG. The line pressure PL generated by the regulator valve 14 is supplied to the torque split clutch A from the line pressure port 13e communicating with the torque split clutch A via the clutch A pressure port 13f. Will be concluded. Further, the direct coupling clutch B is released by the clutch B pressure port 13d communicating with the drain port 13c, and the torque division mode is realized.

When the drive range is selected from the neutral range to the drive range, the speed ratio of the continuously variable transmission 2 shifts from the speed increasing side to the speed reducing side as shown in FIG.
Until it becomes zero, the relationship between the pitot pressure PNS and the pitot pressure PNC is such that PNS> PNC is maintained, and as shown in the lower part of FIG. 7, the torque division mode in a state where the spool 13a is pressed against the left end of the drawing. Is maintained. In the torque division mode, the low-side drive range in which the speed ratio is controlled from the infinite speed reduction ratio to the speed reduction ratio 2.0 is realized by the speed ratio control by the continuously variable transmission 2.

The point at which the reduction ratio of the continuously variable transmission 2 becomes 2.0 is the clutch switching point. At this time, the relationship between the sun gear rotational speed NS and the carrier rotational speed NC becomes NS = NC, and the pitot pressure The relationship between PNS and Pitot pressure PNC is PNS = P
As shown in the upper part of FIG. 7, the spool 13a moves rightward in the drawing, the supply of the line pressure PL generated by the regulator valve 14 to the torque split clutch A is cut off, and the direct connection clutch B The communication with the drain pressure port 13c is also cut off.

Further, when the reduction ratio of the continuously variable transmission 2 exceeds 2.0, the relationship between the sun gear rotation speed NS and the carrier rotation speed NC becomes NS <NC, and the pitot pressure PNS and the pitot pressure P
The relationship with NC is PNS <PNC, and as shown in the upper part of FIG. 8, the spool 13a is pressed against the right end of the drawing, and the line pressure PL created by the regulator valve 14 is equal to the line pressure communicating with each other. The direct connection clutch B is supplied from the port 13e to the direct connection clutch B via the clutch B pressure port 13d, and the direct connection clutch B is engaged. On the other hand, the torque split clutch A is released when the clutch A pressure port 13f communicates with the drain port 13g, and the transmission mode is switched from the torque split mode to the direct connection mode. In the direct connection mode, the gear ratio control by the continuously variable transmission 2 realizes a high drive range in which the gear ratio is controlled from 2.0 on the deceleration side to 0.4 on the speed increase side.

When the neutral range is selected to the reverse range, the torque division mode is maintained as it is, but at this time, the pitot pressure PNR from the unit output rotation direction detecting pitot tube 12 causes the pitot pressure PNR shown in the lower part of FIG. As described above, the spool 13a is pressed to the left by the pitot pressure PNR in addition to the pitot pressure PNS, the pitot pressure PN and the differential pressure, and the torque split clutch A is engaged even when the pitot pressure relationship of PNS <PNC is established. The spool position which is held and in which the engagement of the direct coupling clutch B is prohibited is secured.

Next, the effects will be described.

(1) In the transmission control device for an infinite reduction ratio transmission in which the continuously variable transmission 2 and the planetary gear mechanism 5 are combined, the relationship between the pitot pressure PNS and the pitot pressure PNC is PNS> PNC.
, The torque division mode is set, and the relationship between the pitot pressure PNS and the pitot pressure PNC becomes P via the clutch switching point of PNS = PNC.
Transmission mode switching control for securing the spool position for maintaining the engagement of the torque division clutch A by generating the pitot pressure PNR from the unit output rotation direction detection pitot tube 12 when the vehicle travels backward in the torque division mode when NS <PNC. Since the apparatus is provided with the valve 13, smooth transmission mode switching control can be achieved, and a fail-safe transmission mode switching can be realized when the vehicle moves backward.

(2) The transmission mode switching control valve 13 is connected to the pitot pressure PNS from the continuously variable transmission output speed detection pitot tube 10, the torque split clutch input speed detection pitot tube 11 and the unit output rotation direction detection pitot tube 12. , Pitot pressure PNC,
Since the pitot pressure PNR is used as the operating signal pressure, smooth transmission mode switching control can be achieved by cost-effective and reliable operation, and a fail-safe transmission mode switching when the vehicle moves backwards is realized. Can be.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to the embodiment, and even if there are changes and additions without departing from the gist of the invention, the invention is included in the invention. It is.

[0048] For example, in the embodiment, according to claim 1 for detecting at Pitot pressure the rotational direction with each rotation speed with Pitot tube
Although the example corresponding to the invention described in (1) is shown, the transmission mode switching processing is performed by electronic control using a rotation sensor or a rotation direction sensor and inputting a sensor signal.
It may be an example that corresponds only to the bright.

[0049]

According to the first aspect of the present invention, in the transmission control device for an infinite reduction ratio transmission in which a continuously variable transmission and a planetary gear mechanism are combined, the output speed of the continuously variable transmission is divided by the torque. When the rotational speed is higher than the clutch input rotational speed, only the torque split clutch is engaged, and when the continuously variable transmission output rotational speed is lower than the torque split clutch input rotational speed, only the direct coupling clutch is engaged, and the unit output rotational direction is the reverse direction. In this case, the transmission mode switching control means for maintaining the engagement of the torque split clutch and prohibiting the engagement of the direct coupling clutch is provided, so that smooth transmission mode switching control can be achieved and the transmission mode can be set when the vehicle moves backward. The effect that the fail-safe of switching can be realized is obtained.

According to a second aspect of the present invention, in the transmission control device for an infinite reduction ratio transmission according to the first aspect, the continuously variable transmission output speed detecting means and the torque split clutch input speed detecting means are provided. The pitot tube means for converting the rotation speed into pitot pressure, the unit output rotational direction detecting means as pitot tube means using pitot pressure generated only during reverse travel, and the transmission mode switching control means for each pitot pressure as a signal pressure Since the transmission mode switching control valve operates as described above, smooth transmission mode switching control can be achieved by cost-effective and reliable operation, and a fail-safe transmission mode switching can be realized when the vehicle moves backward. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing a shift control device for an infinite reduction ratio transmission according to the present invention.

FIG. 2 is an overall block diagram showing an infinite reduction ratio transmission to which the transmission control device of the embodiment is applied.

FIG. 3 is a diagram illustrating a relationship between each transmission mode and a speed ratio in the infinite speed reduction ratio transmission according to the embodiment.

FIG. 4 is a pitot pressure characteristic diagram in the example apparatus.

FIG. 5 is a pitot pressure characteristic diagram of the embodiment device when the vehicle is moving backward and when moving forward.

FIG. 6 is a diagram for explaining a pitot pressure generating action in a unit output rotation direction detecting pitot tube of the embodiment device.

FIG. 7 is an explanatory diagram of a valve operation of a transmission mode switching control valve of the embodiment device.

FIG. 8 is an explanatory view of the valve operation of the transmission mode switching control valve of the embodiment device.

[Explanation of symbols]

 a Unit input shaft b Continuously variable transmission c Reducer d Continuously variable transmission output shaft e Reducer output shaft f Unit output shaft g Planetary gear mechanism h Torque split clutch i Directly coupled clutch j Continuously variable transmission output speed detection means k Torque split clutch input rotation speed detection means m Unit output rotation direction detection means n Transmission mode switching control means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 37 / 02,61 / 12 F16H 59 / 38,59 / 40

Claims (2)

(57) [Claims] A continuously variable transmission and a speed reducer connected to a unit input shaft, a sun gear is connected to a continuously variable transmission output shaft, a carrier is connected to a speed reducer output shaft, and a ring gear is connected to a unit output shaft. A connected planetary gear mechanism, a torque split clutch provided in the middle of a transmission path from the unit input shaft to the carrier of the planetary gear mechanism, and a middle part of a transmission path from the sun gear of the planetary gear mechanism to the unit output shaft. Direct-coupled clutch, a continuously variable transmission output rotation number detecting means for detecting the rotation number of the continuously variable transmission output shaft, and a torque split clutch input rotation number detecting means for detecting the input rotation number of the torque split clutch. A unit output rotation direction detecting means for detecting a rotation direction of the unit output shaft; and a torque converter when the output speed of the continuously variable transmission is higher than the input speed of the torque split clutch. Only the split clutch is engaged, and if the output speed of the continuously variable transmission is lower than the input speed of the torque split clutch, only the direct connection clutch is engaged, and if the unit output rotation direction is reverse, the torque split clutch is engaged. And a transmission mode switching control means for inhibiting engagement of the direct coupling clutch while maintaining transmission speed. 2. The speed change control device for an infinite reduction ratio transmission according to claim 1, wherein the continuously variable transmission output speed detecting means and the torque split clutch input speed detecting means convert the speed into a pitot pressure. The unit output rotation direction detecting means is a pitot tube means using a pitot pressure generated only when the vehicle is traveling in reverse, and the transmission mode switching control means is a transmission mode operating as each pitot pressure as a signal pressure. A shift control device for an infinite reduction ratio transmission, which is a switching control valve.